This invention relates to electro ceramic components such as MEMS arrays and methods for fabricating electro ceramic components with high density interconnects so that variable controlled air gaps may be achieved with high accuracy. Components constructed according to the invention are microelectromechanical systems arrays or other micromachined elements.
Conventional MEMS array structures comprise Silicon on Insulator (SOI) array structures on which is fabricated an integrated electrode array. One of the problems encountered is precise control of the distance from the top surface of the electrostatic actuation electrodes and the bottom surface of the MEMS actuation element (hereafter referred,to as the air gap) during fabrication due to limitations of minimum wafer thickness of a SOI wafer where the air gap is nominally set by wafer thickness.
What is needed is a solution that allows for variable controlled air gaps which determine the operating characteristics of a MEMS device that does not compromise the SOI wafer integrity.
According to the invention, in an array apparatus, each MEMS element, comprising an actuatable element and a supportive handle, is mounted over a plurality of electrodes wherein the air gap is controlled by the thickness of the electrodes and not primarily by the structure of the handle. The structure of electrostatic actuation electrodes in specific embodiments is disclosed. While the invention is primarily a technique for reducing the air gap without unduly limiting the thickness of the handle, the invention may also be used to establish an air gap greater than the thickness of the handle.
The invention will be better understood by reference to the following detailed description in connection with the accompanying illustrations.